linux backport

file exists system predicate
$source_file -> $user source
hide and make system preds
fix check_head_and_body
user_expansion never fails
goal expansion is controlled b dynamic procedure
add must_be_of_type predicate_indicator
fix neat_call, debug flag is user controlled
use simplecudd, not ptoblogbdd
compile all of myddas
fx junk in file_name
fix warnings
use common file opening struct and funds
avoid pairs module
fix db queues

packages/ProbLog/problog_examples/queries/input.txt

@@ -1,6 +0,0 @@
-@x0
-0.286554426939
-@x1
-0.517024484197
-@x2
-0.425979613559